Code for a picture to apply filters in frequency domain to it.
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Apply the following filters to any image you prefer in the frequency domain. a. Average filter b. Gaussian filter c. Sharpening filter d. Sobel filter
- To do that: Find the FFT transform of the image,
- Find the FFT transform of the filter (you need to extend the size of the transformed filter so that it’s becomes same as transformed image size)
- Pointwise Multiply the transformed image and transformed filter.
- Find the inverse FFT transformation of the filtered image.
- For every filter give the following: o Original image and its FFT transform o Filter and its FFT transform o Filtered image in frequency domain o Filtered image in spatial domain.
I have tried to figure out this code multiple times, and nothing seems to be working. If someone could help me on this, that would be amazing and I would be forever greatful!
Prachi Kulkarni on 20 Oct 2021
Please refer to the following example for a sample code.
I = imread("cameraman.tif"); % image of size 256x256
I = im2double(I);
F = fspecial("average",3); % average filter of size 3x3
Ipad = padarray(I,[3-1 3-1],0,"post"); % zero padding
Fpad = padarray(F,[256-1 256-1],0,"post"); % zero padding
Ifft = fft2(Ipad);
Ffft = fft2(Fpad);
Offt = Ifft.*Ffft;
Opad = ifft2(Offt);
O = Opad(2:end-1,2:end-1); % remove padding